Threaded Insert Nominal Length (UNF)

Nominal
Diameter		 Pitch
(mm)		 Drill Bit
Diameter (mm)		 Drilling Diameter Tap Nominal Length
min. max. Min Outer
Diameter		 1d 1.5d 2d 2.5d 3d
2-64 0.396 2.3 2.29 2.44 2.70 2.18 3.28 4.37 5.46 6.55
3-56 0.453 2.7 2.62 2.77 3.10 2.51 3.76 5.03 6.30 7.54
4-48 0.529 3.0 2.97 3.14 3.53 2.84 4.27 5.69 7.11 8.53
6-40 0.635 3.8 3.66 3.81 4.33 3.50 5.26 7.01 8.76 10.51
8-36 0.706 4.4 4.32 4.47 5.08 4.16 6.25 8.33 10.41 12.50
10-32 0.794 5.1 5.00 5.16 5.86 4.82 7.24 9.65 12.06 14.48
1/4-28 0.907 6.7 6.55 6.72 7.53 6.35 9.52 12.70 15.87 19.05
5/16-24 1.058 8.3 8.17 8.35 9.31 7.92 11.91 15.87 19.83 23.80
3/8-24 1.058 9.9 9.75 9.93 10.90 9.52 14.27 19.05 23.80 28.57
7/16-20 1.270 11.5 11.39 11.59 12.76 11.11 16.66 22.22 27.78 33.32
1/2-20 1.270 13.1 12.97 13.16 14.35 12.70 19.05 25.40 31.75 38.10
9/16-18 1.411 14.7 14.59 14.79 16.12 14.27 21.43 28.57 35.71 42.85
5/8-18 1.411 16.3 16.18 16.38 17.71 15.87 23.80 31.75 39.67 47.62
3/4-16 1.588 19.5 19.39 19.60 21.11 19.05 28.57 38.10 47.62 57.15
7/8-14 1.814 22.7 22.62 22.84 24.58 22.22 33.32 44.45 55.55 66.67
1″-14 1.814 26.0 25.86 26.11 27.76 25.40 38.10 50.80 63.50 76.20
1″-12 2.117 26.0 25.86 26.11 28.15 25.40 38.10 50.80 63.50 76.20
1″ 1/8-12 2.117 29.2 29.03 29.29 31.33 28.57 42.85 57.15 71.42 85.72
1″ 1/4-12 2.117 32.4 32.21 32.21 34.50 31.75 47.62 63.50 79.37 95.25
1″ 3/8-12 2.117 35.5 35.38 35.38 37.68 34.92 52.37 69.85 87.30 104.77
1″ 1/2-12 2.117 38.7 38.56 38.56 40.85 38.10 57.15 76.20 95.25 114.30

All information is strictly informative